The present invention relates to methods for measuring the humidity or moisture content of crop in an agricultural harvester and, more particularly, to the combination of data from a humidity sensor with data from a mass flow rate sensor.
It is already well known in the art to use data collected during harvester operations for the generation of maps showing the specific yield for each section of a field. To this end, the harvesting machine is equipped with a device for establishing the precise position of the harvester in the yield, such as a Global Positioning System (GPS) receiver, a ground speed sensor, such as a Doppler radar velocity sensor and a crop flow rate sensor, such as a grain mass flow sensor. The data generated by the sensors are logged during harvesting operations and can be used for generating a yield map for a complete field.
Such yield maps provide data on the amount of crop generated by each field portion, but say little on the other qualities of the harvested crop. For instance it may be of interest to have data on the ripeness of the crop. Such data may be derived from humidity or moisture sensors. These data can also assist in deciding whether to continue or interrupt the harvest when the evening is closing in. When the moisture content of the incoming crop material is too high, the efficiency of the threshing mechanism is falling rapidly.
However, such humidity sensors usually require a calibrated volume of crop material, such that dedicated sampling devices are needed for taking portions from the regular crop flow and feeding them into the humidity sensor. An example thereof can be found in U.S. Pat. No. 5,616,851.
It is also known to use a manually operated switch for marking deviating spots in a field during harvest operations. This information is loaded into the memory of the mapping system and is combined with the GPS information for indicating the spots on a map of the field. Such system has already been used for identifying weed spots. However, the reliability of such map is depends completely of the continuous attention of the operator and his quick reaction to the occurrence of such spots.
Accordingly, it would be desirable to provide a method for continuously assessing the humidity of harvested crop without the use of any sampling device.